Given that ACPA and RF seropositivity can be helpful in informing response to treatment with other antirheumatic medications in RA (e.g., abatacept and rituximab), confirming the value of differential prediction of early response to MTX treatment in RA by serostatus in future studies may help to further refine the approach to the management of early RA [37, 38]. This evidence concerns the gene PRTN3 and rheumatoid arthritis.